DSL (Dipole-Source Localization) is a commonly used analysis technique in which an iterative computer search algorithm in a mathematical model is used to find dipoles that can explain a given evoked-response. DSL results lack any direct proof of accuracy. There are good reasons to expect inaccurate results, due to inaccurate parameters in the model. One of the inaccuracies concerns skull and scalp resistivities. The problem is worse with infants because the skull resistivity must change as the calvarium calcifies. The applicant has simulated a method of estimating critical DSL model parameters, knowing that an inaccurate model can be made accurate. The proposed project will test this method in infants and children, using recorded evoked responses. The "gold standard" for accuracy will be based on MRI recordings from the same subjects.